Semiconductor devices are commonly found in modern electronic products. Semiconductor devices vary in the number and density of electrical components. Discrete semiconductor devices generally contain one type of electrical component, for example, light emitting diode (LED), small signal transistor, resistor, capacitor, inductor, and power metal oxide semiconductor field effect transistor (MOSFET). Integrated semiconductor devices typically contain hundreds to millions of electrical components. Examples of integrated semiconductor devices include microcontrollers, microprocessors, charged-coupled devices (CCDs), solar cells, and digital micro-mirror devices (DMDs).
Semiconductor devices perform a wide range of functions such as signal processing, high-speed calculations, transmitting and receiving electromagnetic signals, controlling electronic devices, transforming sunlight to electricity, and creating visual projections for television displays. Semiconductor devices are found in the fields of entertainment, communications, power conversion, networks, computers, and consumer products. Semiconductor devices are also found in military applications, aviation, automotive, industrial controllers, and office equipment.
Semiconductor devices exploit the electrical properties of semiconductor materials. The atomic structure of semiconductor material allows its electrical conductivity to be manipulated by the application of an electric field or base current or through the process of doping. Doping introduces impurities into the semiconductor material to manipulate and control the conductivity of the semiconductor device.
A semiconductor device contains active and passive electrical structures. Active structures, including bipolar and field effect transistors, control the flow of electrical current. By varying levels of doping and application of an electric field or base current, the transistor either promotes or restricts the flow of electrical current. Passive structures, including resistors, capacitors, and inductors, create a relationship between voltage and current necessary to perform a variety of electrical functions. The passive and active structures are electrically connected to form circuits, which enable the semiconductor device to perform high-speed calculations and other useful functions.
Semiconductor devices are generally manufactured using two complex manufacturing processes, that is, front-end manufacturing, and back-end manufacturing, each involving potentially hundreds of steps. Front-end manufacturing involves the formation of a plurality of semiconductor die on the surface of a semiconductor wafer. The term “semiconductor die” as used herein refers to both the singular and plural form of the words, and accordingly can refer to both a single semiconductor device and multiple semiconductor devices. During front-end manufacturing, or fabrication of semiconductor die on a native wafer, each semiconductor die is typically identical and contains circuits formed by electrically connecting active and passive components. Back-end manufacturing can involve singulating individual semiconductor die from the finished wafer and packaging the die to provide structural support and environmental isolation.
Individual semiconductor die and semiconductor packages can be marked with identifiers, such as by printing or laser marking on a backside of the semiconductor die or semiconductor package, to identify, track, or both, semiconductor die and semiconductor packages. As such, the marking of semiconductor die and packages can be done before singulation of the semiconductor die from the native semiconductor wafer, or after singulation and packaging in front-end manufacturing processes, back-end manufacturing processes, or both.
FIG. 1 shows an embodiment of a semiconductor package 2 comprising markings or identifiers 4 as known in the prior art. The markings 4 are formed on an outer surface of the package, such as in or on encapsulant or molding compound by printing or laser marking. The markings 4 can include alphanumeric characters, codes, and other symbols or designs that can include a notch 5 for identifying an orientation of the package 2, a pin identifier, dot, or circle 6 that can identify a first input/output (I/O) interconnect, such as a pin or other I/O interconnect. The markings 4 can also include one or more of a lot-trace code, a device mark, a logo, a date code, fab location, or other desirable information.